Refuse collection vehicles can pick up and empty refuse containers from the front of the vehicle or from the side. Loading from the front of the vehicle as in U.S. Pat. No. 6,071,058 requires sufficient access so the front of the large refuse vehicle can approach the refuse container and such access is not possible in narrow alleys. Also, front loading lifts the refuse container over the vehicle cab and operator posing inherent risks if the container or its contents fall onto the cab during operation. In contrast, side-loading refuse vehicles need only drive alongside a refuse container and the container is lifted over the side of the vehicle rather than over the cab so there are access and safety advantages. Unfortunately, a side loading refuse vehicle cannot always get as close to the refuse container for ease of pick-up compared to a front loading vehicles. Thus, side loading refuse vehicles usually have mechanisms to extend from the vehicle and engage the refuse container and that increases complexity.
Side loading mechanisms exist that use articulated arms as in EP1142803. But the articulation joints are subject to wear and impart lateral movement to the assembly holding the refuse container when the arm is in the extended position.
Current mechanisms for side loading refuse vehicles are illustrated by U.S. Pat. No. 5,702,225 to Ghibaudo, which has a lateral rail extending and retracting the bottom of an arm with a carriage reciprocating along the length of the arm to pick up and empty trash receptacles. A pair of opposing grippers is connected to the carriage and engages a full refuse container resting on the ground. The grippers and refuse container move with a carriage along the length of the arm to lift the container from ground level to the top of the vehicle's refuse compartment. The top of the single-piece arm is curved so the arm resembles an inverted J shape, referred to as a candy cane shape. As the carriage moves along the curved portion, which extends downward, the container is inverted so as to empty the contents into the refuse compartment at the same location on the vehicle. As the carriage moves to the opposing end of the arm by the ground, the empty container is set back on the ground where the grippers release it whereupon the arm is retracted against the vehicle. The top of the one-piece arm was pivotally mounted at the top so the entire arm rotates about that top pivot, with the tip pivot mounted to move vertically relative to the vehicle.
While this is an improvement on prior side loading refuse vehicles. The movement of the arm and carriage rely on a series of pulleys, gears and motors which too often wear, break, or for various other reasons become misaligned sufficiently to require repair. Further, the movement of the carriage, grippers and refuse container and parts around the curved end of the arm caused the container to undergo a rapid acceleration and rotation which comes to an abrupt stop when the carriage hits a stop and that jars the single-piece arm mechanism, contributing to wear, misalignment and breakage. There is thus a need for an improved side loader for refuse vehicles.